Ethylenimine methylol-phosphorus polymers and process of preparation



Uited States Patent a ETHYLENIMINE ivmrnvrot-rnosruouus no y, MERS AND PROCESS or PREPARATION No Drawing. Application November 18, 1953,

Serial No. 393,023

6 C s (G (Granted under Title 35, U. S, Code (1952), sec. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, for all governmental purposes, hroughout the. worl wi h the power o gran su licenses for such Purposes, is hereby granted to the Gov- .ernment of the United States of America.

This invention relates to unique phosphorus and nitrogen containing polymers. More particularly, the invention provides cross-linked flameproof'polymers, the liquid members of which have an unusually high water solubility and the solid members of which have unusually high hydrophilic properties and a resilient sponge-like structure which swells upon contact with water.

This invention is a continuation in part of our co-pending applications, Serial Nos. 283,743 and 283,744, filed April 22, 1952, now U. S. Patents Nos. 2,668,096 and 2,759,903, respectively; Serial 'No. 348,137, filed April 10, 1953, now abandoned; and Serial Numbers 378,435 and 378,437, filed September 3, 1953.

Our corpen'ding applications relate to valuable new methylol-phosphorus polymers produced by reacting at least one compound of the group, tetrakis(hydroxymethyl) phosphonium chloride, tris(hydroxymethyl') phosphine oxide and phosphorus linked methylol group containing derivatives thereof, with nitrogen compounds containing at least two members of the group, hydrogen atoms and methylol radicals, attached to trivalent nitrogen atoms.

The compounds tetrakis(hydroxymethyl) phosphoniuin chloride and -tris (hydroxymethyl) phosphine oxide are herein fter referred ,to by their initials THPC and IHPQ, respectively, and the term *phosphorus compounds is used exclusively to refer to at least one compound of the group THPC, THPO and phosphorus linked methylol group containing derivatives thereof. The phosphorus linked methylol group containing derivatives are the prodwe o r a t n THPC, IHRO, or a mix ure thereof, a

h at .le s one o he ompcuudto rme produ t cona n n t least t o CH20 groups in wh ch th p osphorus atoms are members of pentavalent phosphorus adicals f the group, :uirneth l u phosnhin Oxide,

,(C zb Q an etramet ylene phasphon rn chlorid -(-CH2)4PC n gen a i ac o da ce ith th intent on, thyleni-min m y -p o ho us po mer ar p oduce by reac g at lea on ph pho us omoouud o the oup t ta th o ym t-h rhosp uium chlo ide and h syd ym t yD pho ph ne oxi eand rh spho u iked methylol group containing derivatives thereof an ethylenirnine compound containing cyclic imino radicals of the formula fig (Blip-+ K nvhere :R represents a radical .of the group consisting .of hydrogen, hydrocarbon radicals, and polyethylenimine residue e .Qthylenimine methylol-phosphorus polymers consist of cross-linked polymers containing reoccurringunits p 2,795,569 Patented June 11, 1957 2 of the structures, NCH P and NC(R)2 C(R)2OCH2P, in which R is a radical of the group consisting of hydrogen, hydrocarbon radicals, and polyethylenimi ne residues. As can be seen, the phosphorus atoms in these units are attached to trivalent nitrogen atoms by the structures CH2-- and C(R)2C(R) 2OCHa. The phosphorus atoms themselves are members of pentavalent phosphorus a a of the group c nsi tin 2? r oh e hos in oxide and tetramethylene phosphonium chloride.

Illustrative examples of suitable ethylenimine compounds include ethylenimine, its homologs such as 2- m thyle h eu mi e, its hydrocarbon n log such as r enylethy eu m us; 2, diphs e hy euim ne, ZTmQthYl' 3i -4irheu lsth eu utiue, "the r y y en i s, the products of reaching formaldehyde'with such ethyleniiniue com ounds! an the ike i As the ethylenimine methylol-phosphorus polymers are fo mius they pa s th ou h thre m re r e e efi stages, In these stages the polymers may be regarded as: (a) liqu d co pl el Wa r so u le e uo medium molecular weight semisolid resinoids which, when the ratio of the phosphorus compound or its derivatives is high, are substantially completely water soluble; and (c) res lien s ngy soli re inoids whi h are ins lu le in substantially all'inert liquids] The h eni n us m thy o ho r p m r e useful as resilient solid polymers, as materials for use in the production of flameproof textiles, synthetic plastic articles, protective coatings, paints, varnishes, and the li e Thei unique Propert es of igh Water swellability pronounced hydrgphilic character; and soft resilient physical structure, renders them particularly valuable for use as modifiers, copolymerizing monomers; and plastici z ers fol Oihfi r, ev sius, particularly methylol-phosphorus Po me s- In the production of the ethylenimine methylol phosphorus polymers, the phosphorus compounds, and the nitrogen compounds can be mixed in substantially any prop tions Preferred ethylenimine methylol-phosphorus polymers are prepared by reacting the phosphorus compounds in an aqueous medium with mono or polyethylenimine in the presence .or absence of formaldehyde. The ratio of moles of ethylenimine compound'containing a NH group to moles of phosphorus compound is preferably from about '1 1031 to' .4'to -1. The reaction is' preferably' conducte'd at from 0 to degrees C. i

Preferred phosphorus compounds comprise mixtures of THPC and 'TH-PO predominating in THPC. Such mixtures canbe formed by mixingTHPC and THPO or by reacting THPC with abasic compound until a minor proportion is converted to THPO. Basic compoundssuch as amines, imines or water soluble salts pf carbonic acid can suitably be used, and the conversion can suitably be conducted in situ in the presence of the ethylenimine compound.

Further ro xmeriaa lset leuimin m t o ph ph pql usrs can beiusqlubil z n bul .in solution, or in situ as an impreguant, by the application of heat, and/or by te stig 'th .a giou a- The am n l b liz 't euisas erts. r s eatetdst in -P ingapplieation, Serial lip, 3913,02, l filed of even date, now 1 ?eteat 9- ,2 7. .2 ..18.8-

further polymerigable ethylenimine methylol-phosphorus polymers be reacted with one ormore compounds containing at least one group which yields a condensation product with a phosphorus linked methylol group. Illustrative examples of suitable compounds cont .u P OSRhorusglinked-methylol group-reactive groups as acrylamide, melamine, guanidine and urea, polypeptides such as proteins, water soluble methylol derivatives of such nitrogen compounds, such as the water soluble methylol melamines, phenolic compounds such as phenol, the polyhydroxy benzenes, and the like. Such reactions produce modified ethylenimine methylol phosphorus polymers in which the unique hydrophilic and resilient properties of the ethylenimine polymers modify or are modified by, the properties characteristic of other methylol phosphorus polymers.

The following examples are illustrative of details of the invention. The word parts is used exclusively to refer to parts by weight.

Example 1 A solution of 3.2 parts of ethylenimine in 10 parts of water was mixed with a solution of parts of THPC in 5 parts of water. The ratio of moles of ethylenimine to moles of phosphorus compound was 3 to 1. An exothermic reaction occurred and within two minutes a clear gel formed.

The gel was soluble in water, volume for volume. A portion of the gel was heated to 150 C. for several minutes. The heating produced a hard brown solid polymer which was insoluble in water or alkali. After standing at room temperature (25 C.) for 20 minutes, the polymer became resilient. When four parts of the resilient polymer were mixed with 30 parts of water, the polymer swelled until it occupied the entire volume. The resilient polymer contained 6.2% phosphorus and 14.9% nitrogen on a dry basis.

Example 2 A solution of 1.1 parts of ethylenimine in 4.4 parts of water was mixed with a solution of 5 parts of THPC in 5 parts of water. The ratio of moles of ethylenimine to moles of phosphorus compound was 1 to 1. An exothermic reaction occurred and was controlled by cooling. Within a few minutes the exothermic reaction had stopped and the reaction mixture was a viscous solution.

One part of the solution was spread into a thin layer and heated for minutes at 130 degrees C. The heating produced a hard water soluble polymer which upon standing at room temperature became resilient.

Example 3 A solution of 2.2 parts of ethylenimine and 7 parts of water was mixed with a cool solution (at about 5") consisting of 5 parts of THPC in 5 parts of water. The ratio of moles of ethylenimine to moles of phosphorus compound was 2 to 1. Within about 3 minutes a gel formed. Heating the gel to about 150 C. for a few minutes converted it to a hard polymer which upon standing at room temperature became a resilient polymer.

When three parts of the dry resilient polymer was mixed with 40 parts of water, it swelled to take up the entire volume. The resilient polymer contained 5.7% phosphorus and 12.5% nitrogen on a dry basis.

Example 4 p A piece of 80 by 80 cotton print cloth was impregnated 'with a solution of 5 parts of THPC in parts of water tion containing 0.2% sodium carbonate, retained 1.36%

phosphorus, and would still pass the flame test.

Example 5 A solution of 1 part of THPO in 3 parts of water was mixed with /2 part of ethylenimine. An exothermic reaction occurred and within a few minutes a clear gel formed. When the gel was heated at C. it became a hard brown solid polymer.

The freshly prepared dry polymer was brittle but upon standing in a moist atmosphere for a few minutes, it became resilient. The resilient polymer was substantially completely insoluble in water and swelled materially upon contact with water.

Example6 A solution of 3.2 parts of a viscous liquid polyethylenimine in 10 parts of water was mixed with a solution of 5 parts of THPC in 5 parts of water. An exothermic reaction occurred, and in a few minutes, a clear gel was formed.

The gel was heated for a few minutes at about C., until the gel became a solid-polymer. Upon standing at room temperature the polymer soon became resilient.

Example 7 A viscous solution of a methylol group containing phosphorus compound derivative was produced by reacting THPC with ethyleniminc as described in Example 2. One part of this solution was mixed with a solution of one part of a water soluble methylol melamine containing about 3 methylol groups per molecule in 4 parts of water. The combined solutions were heated for several minutes at about 100 C. until a gel was formed.

The gel was heated for several minutes at about 130 C., until a solid polymer was produced. The polymer was resilient, flexible, and insoluble in water and in aqueous solutions of alkali metal hydroxide.

We claim:

1. A cross-linked polymer containing recurring structural units composed of phosphorus atoms contained in radicals of the group consisting of trimethylene phosphine oxide and tetramethylene phosphonium chloride and which are attached to trivalent nitrogen atoms by connecting structures of the group consisting of CH2 and C(R2)C(Rz)OCH2 in which R is a radical of the group consisting of hydrogen, methyl, and phenyl, said polymer having been produced by reacting, in an aqueous solvent at a temperature from about 0 to C., at least one phosphorus compound selected from the group consisting of tetrakis(hydroxymethyl) phosphonium chloride, tris(hydroxymethyl) phosphine oxide, and phosphorus-linked methylol-group-containing derivatives thereof with an ethylenimine compound of the formula as (Rs) 0 C (B2) wherein R is a radical of the graup consisting of hydrogen, methyl, and phenyl, the ratio of ethylenimine lcompound to phosphorus compound being from about 1:1 to about 4:1.

3. The process of claim 2 in which the phosphorus compound is tetrakis(hydroxymethyDphosphonium chlon'de.

4. The process of claim 3 in which the ethylenimine compound is ethylenimine.

5. A process for producing a phosphorus-containing cross-linked polymer which comprises reacting, in an aqueous solvent at a temperature from about 0 to 160 C., at least one phosphorus compound selected from the group consisting of tetrakis(hydroxymethyl)phosphonium chloride, tris (hydroxymethyl) phosphine oxide, and phosphorus-linked methylol-group-containing derivatives thereof with an ethylenimine compound of the formula wherein R is a radical of the group consisting of hydrogen, methyl, and phenyl, the ratio of ethylenimine compound to phosphorus compound being from about 1:1 to

No references cited. 

1. A CROSS-LINKED POLYMER CONTAINING RECURRING STRUCTURAL UNITS COMPOSED OF PHOSPHOROUS ATOMS CONTAINED IN RADICALS OF THE GROUP CONSISTING OF TRIMETHYLENE PHOSPHINE OXIDE AND TETRAMETHYLENE PHOSPHOROUS CHLORIDE AND WHICH ARE ATTCHED TO TRIVALENT NITGROGEN ATOMS BY CONNECTING STRUCTURES OF THE GROUP CONSISTING OF-CH2AND -C(R2)C(R2)OCH2- IN WHICH R IS A RADICAL OF THE GROUP CONSISTING OF HYDROGEN, METHYL, AND PHENYL, SIAD POLYMER HAVING BEEN PRODUCED BY REACTING, IN AN AQUEOUS SOLVENT AT A TEMPERATURE FROM ABOUT 0* TO 160* C., AT LEAST ONE PHOSPHOROUS COMPOUND SELECTED FROM THE GROUP CONSISTING OF TETRAKIS(HYDROXYMETHYL) PHOSPHONIUM CHLORIDE, TRIS(HYDROXYMETHYL) PHOSPHINE OXIDE, AND PHOSPHOROUS-LINKED METHYLOL-GROUP-CONTAINING DERIVATIVES THEREOF WITH AN ETHYLENIMINE COMPOUND OF THE FORMULA 